1. Field of Invention
The present invention relates to a signal processing method and a computing device, and in particular, to a processing method of a touch signal and a computing device thereof.
2. Related Art
Various kinds of touch input devices have been widely applied to electronic products such as mobile phones and tablets, which are configured with a touch panel serving as the input device. The user can easily operate the input panel by finger to input instructions, control the cursor, or input text by writing.
In general, the touch panels include resistive, capacitive, supersonic, or infrared types. Herein, the resistive touch panel is most popular. The designs of the resistive touch panels include 4-wire, 5-wire, 6-wire and 8-wire resistive touch panels. With considering of the cost and development, the 4-wire resistive touch panel has been applied to many productions and applications.
Besides, when using a middle or large scaled touch screen to writing, the user easily puts his/her palm on the screen, which can cause an undesired palm input event. Unfortunately, the touch screen may treat the undesired palm input event as a touch input operation and thus generate a fault input signal. In order to prevent the fault input signal caused by the undesired palm input event, the conventional art tries to change the structure and design of the touch panel to solve this problem.
Regarding to a resistive touch panel, for example, when the finger presses the touch panel, the thin-film conductive layer disposed between the spacers is deformed so that the thin-film conductive layer is conducted with another conductive layer. The touch panel can present the undesired touch event of palm by configuring the spacers of different distribution densities. For example, if the density of the spacers is increased, the user needs to apply larger pressing force on the touch panel to conduct two conductive layers so as to generate an effective touch input. However, in general, the pressing force caused by finger is smaller, but the pressing force caused by palm or stylus is larger. If the arrangement of the spacers is designed to achieve the palm rejection function, the user must apply larger force to generate effective touch input. Although this method is able to solve the undesired palm touch event, the applied force in finger touch operation must be increased, which may cause inconvenience to the user.
Therefore, it is an important subject of the invention to provide a processing method of a touch signal and a computing device thereof that can exclude the unintentional touch of palm.